mariadb/mysql-test/r/bdb_notembedded.result
unknown aaf6acae9b Bug#27573: MIN() on an indexed column which is always NULL sets _other_ results
to NULL

For queries of the form SELECT MIN(key_part_k) FROM t1 
WHERE key_part_1 = const and ... and key_part_k-1 = const,
the opt_sum_query optimization tries to
use an index to substitute MIN/MAX functions with their values according
to the following rules:
1) Insert the minimum non-null values where the WHERE clause still matches, or
3) A row of nulls

However, the correct semantics requires that there is a third case 2)
such that a NULL value is substituted if there are only NULL values for 
key_part_k.

The patch modifies opt_sum_query() to handle this missing case.


mysql-test/r/func_group.result:
  Bug #27573: Correct result
mysql-test/t/func_group.test:
  Bug #27573: test case
sql/opt_sum.cc:
  Bug #27573:
  Added code that will try to read the
  first non-null value for a given complete-field prefix, second
  choice is to read the null, and lastly set the error code if no row
  is found.
2007-05-15 15:29:12 +03:00

35 lines
1.2 KiB
Text

set autocommit=1;
reset master;
create table bug16206 (a int);
insert into bug16206 values(1);
start transaction;
insert into bug16206 values(2);
commit;
show binlog events;
Log_name Pos Event_type Server_id End_log_pos Info
f n Format_desc 1 n Server ver: VERSION, Binlog ver: 4
f n Query 1 n use `test`; create table bug16206 (a int)
f n Query 1 n use `test`; insert into bug16206 values(1)
f n Query 1 n use `test`; insert into bug16206 values(2)
drop table bug16206;
reset master;
create table bug16206 (a int) engine= bdb;
insert into bug16206 values(0);
insert into bug16206 values(1);
start transaction;
insert into bug16206 values(2);
commit;
insert into bug16206 values(3);
show binlog events;
Log_name Pos Event_type Server_id End_log_pos Info
f n Format_desc 1 n Server ver: VERSION, Binlog ver: 4
f n Query 1 n use `test`; create table bug16206 (a int) engine= bdb
f n Query 1 n use `test`; insert into bug16206 values(0)
f n Query 1 n use `test`; insert into bug16206 values(1)
f n Query 1 n use `test`; BEGIN
f n Query 1 n use `test`; insert into bug16206 values(2)
f n Query 1 n use `test`; COMMIT
f n Query 1 n use `test`; insert into bug16206 values(3)
drop table bug16206;
set autocommit=0;
End of 5.0 tests